Processes for the preparation of indane carboxylates, specifically (+) (1S, 2R, 3S)-3-[2-(2-hydroxyeth-1-yloxy)-4-methoxyphenyl]-1-(3,4-methylenedioxyphen yl)-5-(prop-1-yloxy)indane-2-carboxylic acid and (+) (1S, 2R, 3S)-3-(2-carboxymethoxy-4-methoxyphenyl)-1-(3,4-methylenedioxyphenyl)-5-(p rop-1-yloxy)indane-2-carboxylic acid have previously been described. In particular a multistep process to prepare (+) (1S, 2R, 3S)-3-(2-carboxymethoxy-4-methoxyphenyl)-1-(3,4-methylenedioxyphenyl)-5-(p rop-1-yloxy)indane-2-carboxylic acid in 6% overall yield (not including a racemic separation step) from methyl 3-(prop-1-yloxy)benzoylacetate and a multistep process to prepare (+) (1S, 2R, 3S)-3-[2-(2-hydroxyeth-1-yloxy)4-methoxyphenyl]-1-(3,4-methylenedioxypheny l)-5-(prop-1-yloxy)indane-2-carboxylic acid in 2% overall yield (not including a racemic separation step) from methyl 3-(prop-1-yloxy)benzoylacetate is reported in International Publication Number WO 94/25013, published Nov. 10, 1994. The syntheses of these molecules are complicated by the presence of three chiral centers in each compound.
Processes for the preparation of cyclopentano[b]pyridine derivatives have previously been described. In particular, multistep processes to prepare cyclopentano[b]pyridine derivatives, in low over all yield, are reported in U.S. Pat. No. 5,389,620.
Thus, there is a need in the art for an economical method to prepare indane carboxylates and cyclopentano[b]pyridine derivatives, specifically (+) (1S, 2R, 3S)-3-[2-(2-hydroxyeth-1-yloxy)-4-methoxyphenyl]-1-(3,4-methylenedioxyphen yl)-5-(prop-1-yloxy)indane-2-carboxylic acid and pharmaceutically acceptable salts thereof and (+) (1S, 2R, 3S)-3-(2-carboxymethoxy-4-methoxyphenyl)-1-(3,4-methylenedioxyphenyl)-5-(p rop-1-yloxy)indane-2-carboxylic acid and pharmaceutically acceptable salts thereof.
The numerous advantages of the presently invented process and intermediates will become apparent upon review of the following description.